Directional solidification method and its device for continuous production for polycrystalline silicon ingot

Abstract

The invention provides a directional freezing method for continuously producing polysilicon ingots, relating to an uniform polycrystal material which takes material or shape as characteristics and possesses of a certain structure. The invention provides a directional freezing method for continuously mass production of polysilicon ingots in the process of producing solar energy-level polysilicon by metal silicon in the metallurgy process and a device adopting the method. Empty graphite molds are arranged according to the axial space order and driven to move forward by a furnace vehicle, and the empty graphite molds are preheated in the preheating area; liquid silicon undergoing melt refining is put in the empty graphite molds after preheating; the liquid silicon is kept warm in a high-temperature area of a hearth and enters an intermediate-temperature area; from the high-temperature area to the intermediate-temperature area, the liquid silicon are gradually directionally frozen in graphite molds; frozen silicon is cooled down to room temperature below a revolving track protective cover in the graphite molds to obtain directionally frozen polysilicon ingots. The directional freezing continuous track furnace for continuously producing polysilicon ingots is provided with a furnace body, a furnace hearth, a furnace vehicle track, a furnace vehicle, a front auxiliary cart, a back auxiliary cart, a revolving track, a propelling device and a power supply and temperature control system.

Description

technical field [0001] The invention relates to a uniform polycrystalline material with a certain structure characterized by material or shape, in particular to a directional solidification method and equipment for continuously producing polycrystalline silicon ingots during the process of producing solar-grade polycrystalline silicon from metal silicon by metallurgy. Background technique [0002] At present, solar energy has become the most concerned green energy, and polysilicon is currently the most widely used solar cell material. The preparation process of cast polysilicon ingots has two methods in principle: one is to melt polysilicon in a crucible, and then exchange heat through the bottom of the crucible to cool the crystal, that is, the heat exchange method; the other is to melt the polysilicon in a crucible. The polysilicon is melted and then poured into another crucible to cool. [0003] Internationally famous polysilicon manufacturers such as Japan’s Jingtao, Ge...

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Problems solved by technology

[0007] The purpose of the present invention is to solve the disadvantages of the existing directional solidification method for producing polycrystalline silicon ingots that a directional solidification furnace can only directional solidify one polycrystalline silicon ingot at a time, low output, long production cycle, large energy consumption, complicated equipment, and high production cost. , to provide a directional solidification method for the continuous production of polysilicon ingots in large quantities during the process of producing solar-grade polysilicon from metal silicon by metallurgy

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